Anti-arrhythmic and anti-heart failure effects of low-level electrical stimulation on aortic root ventricular ganglionated plexi

Background It remains uncertain whether low-level electrical stimulation (LL-ES) of the ventricular ganglionated plexi (GP) improves heart function. This study investigated the anti-arrhythmic and anti-heart failure effects of LL-ES of the aortic root ventricular GP (ARVGP). Methods Thirty dogs were divided randomly into control, drug, and LL-ES groups after performing rapid right ventricular pacing to establish a heart failure (HF) model. The inducing rate of arrhythmia; levels of bioactive factors influencing HF, including angiotensin II type I receptor (AT-1R), transforming growth factor-beta (TGF-beta), matrix metalloproteinase (MMP), and phosphorylated extracellular signal-regulated kinase (p-ERK1/2); left ventricular stroke volume (LVSV), and left ventricular ejection fraction (LVEF)were measured after treatment with placebo, drugs, and LL-ES. Results The inducing rate of atrial arrhythmia decreased from 60% in the control group to 50% in the drug group and 10% in the LL-ES group (p = .033 vs. drug group) after 1 week of treatment. The ventricular effective refractory period was prolonged from 139 +/- 8 ms in the drug group to 166 +/- 13 ms in the LL-ES group (p = .001). Compared to the drug group, the expressions of AT-1R, TGF-beta, and MMP proteins were down-regulated in the LL-ES group, whereas that of p-ERK1/2 was significantly increased (all p = .001). Moreover, in the LL-ES group, LVSV increased markedly from 13.16 +/- 0.22 to 16.86 +/- 0.27 mL, relative to that in the drug group (p = .001), and LVEF increased significantly from 38.48% +/- 0.53% to 48.94% +/- 0.57% during the same time frame (p = .001). Conclusion Short-term LL-ES of ARVGP had both anti-arrhythmic and anti-inflammatory effects and contributed to the treatment of tachycardia-induced HF and its associated arrhythmia.